A Caltech Library Service

Er-doped anatase TiO₂ thin films on LaAlO₃ (001) for quantum interconnects (QuICs)

Shin, Kidae and Gray, Isaiah and Marcaud, Guillaume and Horvath, Sebastian P. and Walker, Frederick J. and Thompson, Jeff D. and Ahn, Charles H. (2022) Er-doped anatase TiO₂ thin films on LaAlO₃ (001) for quantum interconnects (QuICs). Applied Physics Letters, 121 (8). Art. No. 081902. ISSN 0003-6951. doi:10.1063/5.0107071.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


Rare-earth ions (REIs) doped into solid-state crystal hosts offer an attractive platform for realizing quantum interconnects that can function as quantum memories and quantum repeaters. The 4f valence electrons of REIs are shielded by 5s and 5p electrons and undergo highly coherent transitions even when embedded in host crystals. In particular, Er³⁺ has an optical transition in the telecom band that is suitable for low-loss communication. Recently, REIs in thin film systems have gained interest due to potential advantages in providing a flexible host crystal environment, enabling scalable on-chip integration with other quantum devices. Here, we investigate the structural and optical properties of Er-doped anatase TiO₂ thin films on LaAlO₃ (001) substrates. By choosing a system with minimal lattice mismatch and adjusting Er-dopant concentration, we achieve optical inhomogeneous linewidths of 5 GHz at 4.5 K. We show that 9 nm-thick buffer and capping layers can reduce the linewidth by more than 40%, suggesting a pathway to further narrowing linewidths in this system. We also identify that Er³⁺ ions mainly incorporate into substitutional Ti⁴⁺ sites with non-polar D_(2d) symmetry, which makes Er dopants insensitive to the first order to local electric fields from impurities and is desirable for coherence properties of Er³⁺ spins.

Item Type:Article
Related URLs:
URLURL TypeDescription
Shin, Kidae0000-0003-0798-6856
Walker, Frederick J.0000-0002-8094-249X
Ahn, Charles H.0000-0003-2921-0346
Alternate Title:Er-doped anatase TiO2 thin films on LaAlO3 (001) for quantum interconnects (QuICs)
Additional Information:This work was supported by the U.S. Department of Energy (DOE), Office of Science, National Quantum Information Science Research Centers, Co-design Center for Quantum Advantage (C2QA) under Contract No. DE-SC0012704. We also acknowledge the use of the Yale MBE on the National Synchrotron Light Source II (NSLS II) floor supported in part by the NSLS II, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.
Group:AWS Center for Quantum Computing
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0012704
Issue or Number:8
Record Number:CaltechAUTHORS:20221121-712406200.20
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:117955
Deposited By: Research Services Depository
Deposited On:02 Dec 2022 16:21
Last Modified:02 Dec 2022 16:21

Repository Staff Only: item control page